thunar-volman: replace udev by libgudev in DEPENDS

fixes:
| checking for gudev-1.0 >= 145... not found
| *** The required package gudev-1.0 was not found on your system.
| *** Please install gudev-1.0 (atleast version 145) or adjust

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>